Modes in a conical horn: new approach

An analytically simple, sufficiently accurate, and self-consistent solution for modes in a conical horn is presented. The eigenfunctions and eigenvalues derived from the simpler solution for the TE and TM modes of different orders are close to the exact solution. Application of the simpler solution for obtaining the aperture field and, subsequently, the far-field-radiation patterns of conical horns of arbitrary flare angles excited in the TE11 mode, with the aid of a vector diffraction formula, yields results in close agreement with experiment. The new approach provides a simple and accurate solution for the balanced hybrid modes in corrugated conical horns with small and wide flare angles, emphasising the more general validity of the technique adopted.